1. Field of the Invention
The present invention relates to the field of power management, such as the power management of a data storage system adopting a Serial Attached Small Computer System Interface (Serial Attached SCSI or SAS) technique, and more particularly, to a method for performing power management in an electronic system, and an associated apparatus.
2. Description of the Prior Art
A conventional data storage system, such as those implemented with the SAS technique or an SAS expander, may lack a power management scheme. When the conventional data storage system is set up and provided with power, it may operate continuously, unless power outage or power failure occurs, in which case it will stop operating. In another example, when building a plurality of storage modules (e.g. a plurality of conventional enclosures) of the conventional data storage system and a conventional enclosure is installed to a cabinet (or a frame) which has the ability of providing power, the conventional enclosure will operate continuously unless power outage or power failure occurs.
Since each conventional enclosure in the conventional data storage system may install more than twenty hard disk drives (HDDs), the overall power consumption of the conventional data storage system is very high. Without a proper power management scheme, much power will be consumed when the conventional data storage system accesses the hard disk drives therein. When a data access request is not needed, the access operation of each of the HDDs within the aforementioned conventional enclosure may be temporarily suspended, thus reducing the power consumption thereof. Taking a scheme comprising two headers and fifteen enclosures as an example, however, the overall power consumption of the conventional data storage system may still exceed 3500 Watts.
From the above it is therefore demonstrated that the HDDs in the conventional data storage system consume much power when being accessed. Although the overall power consumption may be somewhat reduced due to suspending of the HDDs in each enclosure, the power consumption of the conventional data storage system is still very high. Therefore, there is a need for a novel method and an associated scheme to save power.